Fix checkstyle

Author: Abacn

sdks/java/testing/junit/build.gradle

@@ -32,6 +32,7 @@ dependencies {
   // Needed to resolve TestPipeline's JUnit 4 TestRule type and @Category at compile time,
   // but should not leak to consumers at runtime.
   provided library.java.junit
+  permitUnusedDeclared(library.java.junit)
 
   // JUnit 5 API needed to compile the extension; not packaged for consumers of core.
   provided library.java.jupiter_api

sdks/java/testing/junit/src/main/java/org/apache/beam/sdk/testing/TestPipelineExtension.java

@@ -24,7 +24,7 @@
 import java.util.Collection;
 import org.apache.beam.sdk.options.ApplicationNameOptions;
 import org.apache.beam.sdk.options.PipelineOptions;
-import org.apache.beam.vendor.grpc.v1p69p0.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;